The European Commission will enact a two-year ban on a class of pesticides thought to be harming global bee populations, the European Union’s health commissioner said Monday.

“I pledge to do my utmost to ensure that our bees, which are so vital to our ecosystem and contribute over €22 billion annually to European agriculture, are protected,” Tonio Borg said in a statement from Brussels, where the commission is based.

Mr. Borg made the announcement after representatives of the 27 E.U. member states failed for the second time in two months to reach a binding agreement on a proposal to ban the pesticides, known as neonicotinoids. The commission had proposed the ban after the European Food Safety Authority recommended in January that use of the pesticides be restricted until scientists determined whether they were contributing to a die-off in bee colonies.

“The proposal is based on poor science and ignores a wealth of evidence from the field that these pesticides do not damage the health of bees,” John Atkin, Syngenta’s chief operating officer, said Monday in a statement.